How To Fix /IWBEP/CM_MGW_RT159 - ABAP Dictionary type '&1' not supported (flat structure only)

SAP Error Message - Details

• Message type: E = Error

• Message class: /IWBEP/CM_MGW_RT -

• Message number: 159

• Message text: ABAP Dictionary type '&1' not supported (flat structure only)

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message /IWBEP/CM_MGW_RT159 - ABAP Dictionary type '&1' not supported (flat structure only) ?

  The SAP error message /IWBEP/CM_MGW_RT159 indicates that there is an issue with the ABAP Dictionary type being used in the context of an OData service. Specifically, the error states that the type is not supported because only flat structures are allowed.
  Cause:
  This error typically occurs when you are trying to expose a complex data type (like a nested structure or a table) in an OData service. OData services in SAP Gateway only support flat structures for the data types that can be exposed. If your ABAP Dictionary type is a complex type (e.g., it contains nested tables or structures), the OData service cannot process it, leading to this error.
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Check the Data Type: Review the ABAP Dictionary type that is causing the error. Ensure that it is a flat structure. If it is a complex type, you will need to modify it.
  
  
  Modify the Structure: If the structure is complex, consider flattening it. This means you should remove any nested structures or tables and create a flat structure that contains only simple data types (like CHAR, NUMC, etc.).
  
  
  Create a New Flat Structure: If necessary, create a new flat structure in the ABAP Dictionary that meets the requirements for OData services.
  
  
  Update the OData Service: After modifying the structure, update the OData service to use the new flat structure. You may need to regenerate the service and re-activate it.
  
  
  Test the OData Service: Once the changes are made, test the OData service to ensure that it is functioning correctly without the error.
  
  
  Related Information:
  
  OData Services: Understand the limitations of OData services in SAP Gateway, especially regarding the types of structures that can be exposed.
  ABAP Dictionary: Familiarize yourself with the ABAP Dictionary and how to create and modify data types and structures.
  SAP Gateway: Review the documentation for SAP Gateway to understand how to work with OData services and the requirements for data types.
  
  By following these steps, you should be able to resolve the error and successfully expose your data through the OData service.